The present invention relates to a method and apparatus for use during casting of metal and more specifically to a baffle which is effective to at least partially block heat transfer from a furnace assembly as a mold is moved out of the furnace assembly.
A known apparatus for use in casting one or more metal articles includes a baffle which is connected with a furnace assembly. A chill plate is raised to move a mold supported by the chill plate through the baffle into the furnace assembly. During withdrawal of the mold from the furnace assembly, flexible segments of the baffle engage the mold to at least partially block the transfer of heat from the furnace assembly. This known baffle is disclosed in U.S. Pat. No. 4,969,501 to Brockloff, et al.
The present invention relates to a method and apparatus which is used during casting of molten metal in a mold structure. The mold structure may have a single article mold portion or a plurality of article mold portions depending upon whether one or more articles are to be cast in the mold structure. The apparatus includes a movable chill plate which supports the mold structure in a furnace assembly. An improved baffle is provided to retard transfer of heat from the mold structure when the mold structure is in the furnace assembly and during withdrawal of the mold structure from the furnace assembly.
It is contemplated that a base of the baffle may be constructed with either a circular or noncircular opening. When a plurality of articles are to be cast, the baffle may have a base with a noncircular opening. The noncircular opening may have lobes in which article mold portions of a mold structure for casting a plurality of articles are received. Flexible segments may extend from the base of the baffle into engagement with surfaces of the article mold portions of the mold structure.
The chill plate is lowered to withdraw the mold structure from the furnace assembly. During at least a portion of the withdrawal of the mold structure from the furnace assembly, the article mold portions of the mold structure are disposed in the lobes of the noncircular opening in the base of the baffle. As the mold structure is withdrawn from the furnace assembly, the flexible segments of the baffle at least partially block transfer of heat from the furnace assembly. In certain circumstances, it may be desired to omit the flexible segments.
When one or more articles are to be cast, the baffle may be positioned relative to the mold structure with the baffle extending around a portion of the mold structure and with flexible segments of the baffle disposed in engagement with the mold structure. The mold structure may be positioned on the chill plate either before or after the baffle is positioned relative to the mold structure. The chill plate, mold structure and baffle may be moved upward toward the furnace assembly to move at least a portion of the mold structure into the furnace assembly with the baffle extending around the mold structure. After molten metal has been poured into the mold structure, the chill plate and mold structure are moved downward relative to the furnace assembly and baffle. As the mold structure is moved downward, flexible segments of the baffle engage the mold structure to at least partially block heat transfer from the furnace assembly.
The baffle may advantageously be positioned relative to the mold structure by a projection. The projection may be formed by a thermocouple assembly which extends from the chill plate into the baffle. Alternatively, the mold structure may be formed with a projection which extends from the mold structure into the baffle. If desired, a member which is separate from the mold structure and the baffle may be moved through an opening in the baffle and the mold structure into an opening in the chill plate.
The baffle may be formed with a one piece base. The baffle may also include one or more sheets of material which form a seal in which the flexible segments are formed. The sheet or sheets of material and base of the baffle may each be maintained as one piece. Alternatively, the sheet or sheets of material and base of the baffle may be divided into a plurality of sections which are positioned relative to the mold structure.